1. Technical Field
The present disclosure relates to an optical waveguide, which can transmit light, an optical waveguide mounting substrate, and a light transmitting and receiving device.
2. Related Art
In recent years, with the high density interconnection of the internal structure of integrated circuits, Central Processing Units (CPU) and the like have higher operating speeds (operating clock). However, the signal transmitting speed in an electrical transmission system has almost reached a limit, and the processing speed of the CPU and the like is bottlenecked. In addition, the high operating speed (operating clock) of the CPU and the like is accompanied by problems such as crosstalk noise or EMI (Electromagnetic Interference noise), which occur due to the high density interconnection. Accordingly, there remains a strong need for measures that can prevent such noise.
As an approach to solve these problems, an optical interconnection system using an optical waveguide is gaining attention. The optical interconnection system can carry out much wider broadband transmission than the electrical transmission system, cope with the high processing speed, and build up a signal transmission system using small, low power consumption optical components. Also, the optical interconnection system can suppress the crosstalk noise or the EMI noise. The optical waveguide generally has a reflecting mirror on one end thereof. The reflecting mirror is an inclined surface formed at an angle of about 45°, which serves to change the transmission direction of light (see e.g., JP-A-2002-006161 and JP-A-2002-365457).
However, in the related-art optical waveguide, a metal film, for example, of Au needs to be formed on the inclined surface by deposition or spattering in order to change the transmission direction of light. This disadvantageously increases the fabrication cost of the optical waveguide.